Apparatus for washing and wet screening



Sept. 11, 1923.

N. C. CHRISTENSEN APPARATUS FOR WASHING AND'WET SCRBFNING Filed March 1921 I J/WENTOR.

7M C. W.-

Lim

Patented Sept. '11, 1923.

UNIT o; STATS NIELS C. CHRISTENSEN, OF SALT LAKE CITY, UTAH.

APPARATUS WASHING AND WET SCREENING.

Application. filed March 8, 1921. Serial No. 450,678.

To all whom it may concern:

Be it known that I, Nuns C. Crinrs'rnnsaw, a citizen of the United States, residing at Salt La 'e City. in the county of Salt Lake and State of Utah, have invented"cei'-' tain new and usefulimprovements in Ap'- paratus for lVashing and \Vet Screening, of which the following is a specification.

This invention relates to apparatus .tor washing andwet screening or sizing. The invention is applicable to simple washing operations such as the washing ofgrains and fruits, or the washing of ores to remove clay or sand from coarser lumps of ore. It is also applicable to the wet screening or sizing of crushed ores and other products. It is applicable to the washing,

and screening of the coarsest materials, re-

- quiring massive grizzlies to support the material to be washed, to the finest screening or sizing operations requiring s-rcns of very fine mesh.

In the apparatus the supporting device used in the washing operation may be either a stationary or revolving grizzly or a shalt ing screen or trouuncl and the screening cle vice may be either a trommel or shaking screen or travelling belt screen. The particularkind of supporting or screening device used will depend on the nature of the material and the purpose of the operation and no novelty orinvention is claimed for 'the use of any of these except; in the manner and' as a part of the combination with the other part of my inventionwhich is entirely novel. i p

The method of washing or wet screening used in my invention consists in the application of a spray of water :0 the material to be washed or screened as this ng aterial is passed through or over the supporting grizzly trommel or screen. No claim is made for the use of a spray for washing or s reening since' this is old in the art. but the particular method and special device used to secure this spray and the combination of this device with the different supporting and screening devices is the invention which I desire to patent.

My method of making a spray consists in bringing the surface of a body of water used for spraying into contact with the lower part of a cylinder revolving rapidly about a horizontal axis. The surface of the; water should be maintained at such a level that which the top of the pulley is pulley is moving and requiring the cylinder is approximately tangent to the I surface but so that it dips slightly into the density of the spray will'depend upon the speed of the pulley and the depth to which the pulley dips into. the water. In a general way it may be stated that the higher the speed of the cylinder the finer the spray and the reater the quantity, the cylinder dips into the water the coarser the spray and the larger the amount.

To secure the greatest efficiency the pulley should not be allowed to dip too'deeply into and the deeper the-water, i. e.,' to be immersed in the Water 4 to any considerable extent, as the power re-' quired to throw a given quantity-of spray is greatly increased if the pulley dips deeply into the water and if partially immersed the spraying 'etfectis destroyed For ex ampleusing a twelve'inch diameter ulle one foot: long running at 700 750 R. It

dipping about inch into the .water,'a unit'orm light fan of spray is thrown and about 10 watts are used by the driving motor to throw the spray; dipping inc-l1, a heavy uniform 'fan of spray is thrown, requiring. about 20 watts; dipping i inch, a dense uniform fan of spray is thrown requiring about. 40 watts; dipping inch, a-

very dense spray fan of spray composed of larger dropsis thrown, requiringabout 80 watts; dipping 1 inch, the fan of spray begins to be distorted and is thrown mostly toward the side toward which the top ofthe pulley is moving and is composed of large drops, particularly oni'the side away from moving, and requires about 180 watts; dipping l-la'nches, the fan of spray isentirely only half a fan being thrown on the side to ward which the top of the pulley is moving, and about. 250 watts are used; dipping 1:3} inchesthe fan of spray is entirely distorted being about a the total fan and thrown 'toward the side toward which the top of the about 280 distorted and v 1 effect is entirely destroyed, the onl mamas v the top of the pulley and requiring about 360 wattsydipping 3 inches, the spraying effect being the splashing of a mam 0 water around.- the pulle and requiring about 450-500 watts. he amount of water thrown as spray is practically proportional to the power used up to a dipping depth'oi inch, being about 40 gallons per foot length of cylinder with a 12 inch diameter cylinder dip ing 2; inch and revolving about 750 R. M. and requiring about H. P. to throw the spray, is exclusive of the friction of the driving mechanism.

From the foregoing it will be seen that the efficiency of my invention as a spray making machine declines very rapidly as the depth to which the pulley dips increases over inch and at a depth of three inches is zero.

The density or amount of spray and coarseness of the spray desired will vary with the requirements of the washing or screening operation and may be varied by the level of the overflow in the trough containing the spray water.

As will be noted the power required to throw the spray is extremely small as compared with other means such as nozzles and also that there is no possibility of clogging the spray making device such as is the case with such devices as nozzles. It will also be noted that the water for washing or spraying may be used over again any desired number of times by allowing the sprayed water to run back into the launder beneath the cylinder. It should also be noted that it is possible with my invention to secure an ellicient counter-current of wash water and material to be washed or sized thus securing the maximum possible efliciency in the use of the wash water. It will be apparent to those skilled in the art that these features are of great importance in washing and wet screening devices. It should also be noted that my spray making device may be combined with practically any form of grizzly, trommel, shaking screen or belt screen in a number of different ways so as to secure a very largenumber of combinations suited to practically any required washing or screening operation. It will be apparent to those skilled in the art-that this is also a feature of great importance as related to the usefulness and wideness of applica tion of any washing or screening device,

The drawings show a few of the combinations of my spray making device with different forms of washing and screening dCYlCOS. Fig. 1 shows a vertical cross section of Fig. 2 which is a longitudinal section of my spray making device with a rotating trommel or grizzly. Fig. 3 1s a cross section similar to Fig. 1 showing three trommels (or grizzlies)j instead of one, used in the same housing with a single spray impeller. Figs. l, 5 and 6 show the combination of my spraying device with a travelling beltscreen. Fig. 5 is a longitulinal section and Fig. 4 a cross section 'of the apparatus as arranged tosecure a counter current of wash water and material, and Fig. 6 a. partial longitudinal section similar to Fig. 4 showing a different arrangement of impeller in which no counter current is secured. Fig. 8 shows a longitudinal section of a combination of my spray impeller with a horizontal shaking screen. Fig. 7 is a vertical cross section of Fig. 8. Fig. 9 is a vertical section of the combination of my. spray impeller with a stationary sloping grizzly.

All these different forms of washing and screening appartus are combinations of my spray making device with different forms of supporting or screening devices. It will be apparent that many other combinations and arrangements are possible.

All the different forms of my invention consist in general of a cylinder (1) arranged to revolve about a substantially horizontal axis on a shaft (2) supported in suitable bearings (3) and driven by any suitable pulley or other device (4); a trough (5) with suitable overflow (6) Or other devices to maintain the water level so that the cylinder dips slightly into the waterto the depth desired, and supplied with inlet (7) and outlet (8) pipes or launders to secure the desired flow of water; a housing (9) surrounding the spray impeller (l) and the most cases as the impeller throws a very large fan of spray, for example a 12 inch diameter impeller revolving at 750 R. P. M. th1'o.ws.a solid fan of spray of the width of the impeller and'approximately eight feet high and over ten feet on each side of the impeller.

The action of the apparatus is as follows: The spray impeller (1) is rotated at the diasired speed and the required flow of water is supplied through the inlet (7 and main tained at the desired level by the overflow (6). The material who washed or screened or sized is fed to the grizzly, 'trommel, shalling screen, or perforated belt (10) through the feed spout (11) and is passed through the trommel (or rotating grizzly) or over the grizzly or screen and the oversize is v thereon and carrying the dirt or finer um,-

te-rial down through the openings into the trough (5) beneath. The apparatusmay be applied to the washing of large pieces of ore in a massive rotating grizzly or to the wash ing of fragile fruit or berries which must behandled with care. These various applications will be brought out in the following descriptions of the drawings- Fi s. 1 and 2 show a form of my invention t at may be used for any washing or screening operation 1n which it is desired to secure a countercurrent of washwater and material to bewashed. This apparatus consists of a rotat I ing trommel or grizzly (10) which may slope slightly toward the .dischar e end or may be larger at the discharge en or may be supplied with a spiral projecting inward from the screen so. as to cause the material supplied through the feed spout (11);,0 move to the discharge end (12). -To secure a countercurrent of wash water and material to be Washed the wash water is supplied to the trough; at the opposite end to the feed spout (11) through the inlet pipe (7) and the overflow is discharged from the overflow and outlet (8). The water'in the form of spray is thrown through the openings in'the trommel or grizzly (10) and brought into contact with material to be washed or screened and a counter-current flow of water and material is secured. This type of apparatus may he used fo'r a large variety of pur- DOSES For washing large. pieces of ore or hreaking up large pieces of finer material wh ch cling together. the supporting or screening device (10) may be a rotatings grizzly. For washing wheat or other grains or fruits or berries or torscrecning crushed ore a rotating screen trommel (10) may be used. The form of the housing and the nature of the screen will depend on the use to which the apparatus is to be put. The appawashing may be ut lized for air washing.

The space enclosed in the housing may be divided by a partition (13) (shown dotted) and air to be washed may be passed through the'spruy in the space (14) entering through the-inlet 15) and being discharged through the outlet (16). Such a form of my apparatus is useful in small flour mills. The extension (17) of the trommel is used for draining the washed material. The 'form of s my invention shown in Figs. 7 and 8 is similar to the form ust described except that a shaking screen (10) is used instead of a'rotating grizzly o'r trommel. I The material to be washed or screened is fed onto the shaking screen (10) through the feed spout (l1) and carried forward by the motion f the screen and discharged through the discharge spout (12). The screen (10) is supported inside the housing (9) by the hangers,(19)

and moved back and forward by theccentrie and rod (21). Any suitable mechanism for supporting the screen and giving it the desired motion may be used. The wash water is supplied through the inlet pipe (7) and discharged with the (lit or.

fine material in suspension through theoutlet (8). 'The desired water level is maintained by the overflow (6). vWhile passing through the apparatus the water is thrown up through the openings in the screen (10) washing the material on the screen and carrying the fines down' into the trough (5).

As will be seen the water and material to.

be washed pass through the apparatus in opposite directions thus securing a countercurrent flow of the two. This form of my apparatus is suitable for the washing of grains or truits'or the screening of crushed ore. As shown in the drawingsthe housing (10) in this case will be of any suitable shape to enclose the spray.

The form of my apparatus shown in Figs. fl and 5 are similar to those described in the screen belt (10) is used instead of a trommel or grizzly. Thescreen is s'upported'and .forcgoing except that aperforated belt or moved by the pulleys (22) so that the upperj terial to be washed is fed onto the perforated belt (10) and passed through the housing (9) and discharged into the hoppcr-(23). The washing action of the spray and the counter-current flow of wash water and material to be washed is similarto that described for the two previously described forms of my invention. This form of mv invention 18 suited to the washing of fragile fruits and berries'and to the screening or sizing of finely ground ore. If it is-uot desired to secure a counter current flow as previouslydescribed the axis of the spray impeller (1) may be transverse to the direction of movement of the. belt as shown in.

6. Fig. 9 showsa form of my invcn tion using a sloping screen or grizzly .(25) over which the materialto be. washed slides i claims as interpreted in relation to these.

Having described In invention what I claim and desire to hol is:

l. The washing and wet screening device which consists of a screening device arranged to support material to be washed and to move such material from a receiving end to a discharge end of said device, in combination with a spray making device consisting of a cylindrical surface arranged to revolve rapidly around a horizontal axis and a trough beneath said cylindrical surface arranged to contain liquid to be used as a spray for washing and having an inlet and an outlet for said liquid and arranged to maintain the surface of liquid therein at such a level that said cylindrical surface will dip slightly into liquid contained therein. said screening device and said spraying device being so arranged that spray thrown by said spray making device will pam through the openings in said screening device and will wash material carried by said screening device.

2. The washing and wet screening device which consists of a screening device .arranged to support material to be washed and to move such material from a receiving end to a'discharge end of said device, in combination with a spray making device consisting of a cylindrical surface arranged to revolve rapidly around a horizontal axis and a trough beneath said cylindrical surface arranged to contain li uid to be used as a spray for washing and having an inlet and an outlet for said liquid and arranged to maintain the surface of liquid therein at such a level that said cylindrical surface will dip slightly into liquid contained therein, said screening device and said spraying device being so arranged that spray thrown by saidspray making device will pass through the openings in said screening device and will wash material carried by said screening device, and said devices being enclosed within a housing arranged to contain such said spray and to return such said spray to the above said trough.

3. The washing and wet screening device which consists of a screening device arranged to support material to be washed and to move such material from a receiving end to a discharge end of said device, in combination with a spray making device consisting of a cylindrical surface arranged to revolve rapidly around a horizontal axis device being so arranged that spray thrown by said spray making device will pass through the openings in said screeningdevice and will wash material carried by said screening device, and said screening device being arranged to move material to be washed in one direction parallel to above said axis of said cylindrical surface and said trough being arranged so that washing liquid supplied thereto will flow in the opposite direction parallel to said axis.

4. The washing and wet screening device which consists of a screening device arranged to support material to be washed and to move such material from a. receiving end to a discharge end of said device, in combination with a spray making device consisting of a cylindrical surface arranged to revolve rapidly around a horizontal axis and a trough beneath said cylindrical surface arranged to contain 1i uid to be used as a spray 01 washing and aving an inlet and an outlet for said liquid and arranged to maintain the surface of liquid therein at such a level that said cylindrical surface wil dip slightly into liquid contained therein. said screening device and said spraying device being so arranged that spray thrown by said spray making device will pass through the openin in said screening device and will was material carried by said screening device, and said screening device being arranged to move material to be washed in one direction parallel to above said axis ofsaid cylindrical surface .anl said trough being arranged so that washing liquid vsupplied thereto will flow in the opposite direction parallel to said axis, and said devices being enclosed within a housing arranged to contain such said spray and to return such said spray to the above said trough.

5. The washing and wet screening device which consists of a screening device arranged to support material to be washed and to move such material from a receiving end to a discharge end ofq said device, in combination with 'a' spray making device cqnsisting of a cylindrical surface arranged o revolve rapidly around a horizontal axis and a trough beneath said cylindrical surface arranged to contain li uid to be used as a spray for washing and aving an inlet and an outlet for said liquid and arranged to maintain the surface of liquid therein at such a level that said cylindricalsurface will dip slightly into liquid contained therein, said screening device and said spraying device being so arranged that spray thrown said spray making device will pass throughfthe openings in said screening device and will wash ma terinl carried by said screening device, all aring device and the finer material will be washed down into said trough and the coarser material will be discharged from the discharge end of said screening device.

6. The washing and wet screening device which consists of a screening device ar ranged to support material to be washed and to move-such material from a receiving end to a discharge end of said device, in combination with' a spray making device consisting of a cylindrical surface arranged to revolve rapidly around a horizontal axis and a trough beneath said cylindrical surface arranged to contain liquid to be used as a spray for washing and having an inlet and an outlet for said liquid and arranged to maintain the surface of liquid therein at such a level that said'cylindrical surface will dip slightlyinto liquid contained therein. said screening device and said spraying, device being so arranged that spray thrown by said spray making device' will pass through the openings in said screening device and will wash material carried by said screening device, and said devices being enclosed withinla housing arranged to contain such said spray and to return such said spray to the above said trough, all arranged so that when material to be washed is supplied to said screening device and wash solution is supplied to the receiving and of said trough and said cylindrical surface is rapidly revolved, that said material carried by said screening device will be washed by spray thrown by said spray making dcvice and the finer material will be washed down int said trough and the coarser material will be discharged from the discharge end of said screening device.

. 7. The washing and wet screening device which consists of a screening device arranged to support material to be washed and to move such material from a receiving end tov a discharge end of said device, in combination with a spray making device consisting of a cylindrical surface arranged to revolve rapidly around a horizontal axis and a trough beneath said cylindrical surface arranged to contain liquid to be used as a spray for washing and having an inlet and an outlet for said liquid and arranged.

to maintain the surface wof liquid therein at such a level that said cylindrical surface will dip slightly intoliquid contained therein, said screening device and said spraying device being so arranged that spray thrown by said spray making device will pass through the openings in said,

screening device and will wash material carried by said screening device, and said scrcening device being arranged to inove material-to be washed in one direction parallel to above-said axis of said cylindrical surface and said trough being arranged so that washing liquid supplied thereto' will flow in ,tlie opposite] direction parallel to said axis, all arranged so that when ma the receiving end of said trough and said cylindrical surface is rapidly revolved, that said material carried by said screening device will bewashed bys'pray thrown by said spray making device and the finer material will be washed down into said trough and the coarser material will be discharged from 8, The washing and wet screening device which consists ofa screening device arranged to support material to'be washed and to move such material from a receiving end to a discharge end of said device,.in combinadip slightly into liquid contained therein,

said screening device and said spraying device being so arranged that spray thrown by said spray-making device will pass through the openings in said screening device and W111 wash material carried b sa-zd screening device, and sa d screenlng .evlce terial to be washed is supplied to said screening device and wash solution is supplied to "the discharge end of said screening device. I

.tion'with a spray making device consisting being arranged to move material to be" washed in one direction parallel to above said axis of said cylindrical surface and said trough being arranged so that washing liquid supplied thereto will flow in the op posite direction parallel to said axis, and said devices being enclosed w'ithiua housing arranged to contain such said spray and to return such said spray to the above said trough, all arranged so that when material to be washed is supplied to said screening device and wash solution is supplied to'the receiving end of said troughand said ylindrical surface is rapidly revolved, that said material carried by said screening device will be washed by spray thrown bysaid spray making device and the finer material will be Washed down into said trough'end the coarser material, will be discharged from the discharge end of said screen ng device. a

9. The Washing and wet screening device which consists of a screening device arranged to support material to be Washed and to move such material from a receiving end to a discharge end of said device, in combination with a spray makingdevice consisting of acylindrical surface arranged to revolve rapidly around a horizontal axis and a trough beneath said cylindrical surface as ranged to contain liquid to he used as a spray for washing andhaving an inlet and an outlet for said liquid and arranged to maintain the surface of liquid therein at such a level that said cylindrical surface will dip slightly into liquid contained therein, said screening device and said spraying device being so arranged that spray thrown by said spray making device will pass through the openings in said screening device and will wash material carried by said screening device, and means for removing settled material from said trough.

10. The washing and wet'screening device which consists of a screening device arranged to support material to be washed and to move such material from a receiving end to s discharge end of said device, in combination with a spray making device, consisting of a cylindrical surface arranged to revolve rapidly around a horizontal axis and a trough beneath said cylindrical surface arranged to contain liquid to be used as a screening device, and said screening device being arranged to move material to be" washed in one direction arallel to above said axis of said cylindrice surface and said 1' trough being arranged so that washing liquid supplied thereto will flow in the opposite di-' rection parallel to said axis,' and means for removing settled material froth said'trough. In testimony whereof I have signed my name to this specification.

NIELS C. CHRlSTENSEN. 

